The invention relates to a spinning machine for pneumatic false-twist spinning having a plurality of spinning points with one drafting unit respectively, at least two air nozzles being connected behind a pair of delivery rollers of a drafting unit and being pivotable around a swivel shaft from an operating position into a servicing position.
In a spinning machine of the initially mentioned type described in German Patent Document DE-A 36 38 110, two air nozzles respectively are connected behind the drafting units and can each be swung about separate swivelling shafts from the operating position into a servicing position. So that the respective successive air nozzles arrive in different servicing positions in which they are accessible, for example, to a cleaning operation, two movements respectively are required.
It is also known in a spinning machine described in German Patent Document DE-A 34 11 577 to arrange the air nozzles of the individual spinning points so that they can be slid on slide rods transversely with respect to the drafting units from the operating position into a servicing position. However, a shifting movement of this type is not sufficient if one or several air nozzles are provided that are arranged behind one another because then the individual air nozzles are not easily accessible at their inlet openings and/or outlet openings in the servicing position.
It is an object of the invention to develop a spinning machine of the initially mentioned type such that, also in the case of spinning points with several air nozzles arranged behind one another, a servicing position can be reached in a simple manner in which the air nozzles are easily accessible for servicing work.
This object is achieved in that the air nozzles of each spinning point can be brought into servicing positions that deviate from one another by means of an actuating movement.
The construction according to preferred embodiments of the invention is particularly suitable for fully automated spinning machines which are equipped with a movable servicing carriage. The servicing carriage requires only one actuating element in order to expose both air nozzles in a generous manner for a servicing operation, particularly for a cleaning.
In an advantageous development of the invention, it is provided that the air nozzles are held in a common holding device which can be swivelled around a first swivel shaft and at which one of the air nozzles is held so that it can be swivelled around a second swivel shaft, in which case the air nozzle which can be swivelled around the second swivel shaft is connected by means of a transmission mechanism with the first swivel shaft which transmits the swivel motion of the holder around the first swivel shaft into an additional swivelling motion of the air nozzle around a second swivel shaft.
This transmission mechanism therefore provides that both air nozzles move apart so that they depart from the relative position which they take up in the operating position. In an advantageous implementation of this development, it is provided that a toothed wheel segment is mounted at the first swivel shaft which mates with a toothed wheel segment connected with the air nozzle which can be swivelled around the second swivel shaft which is in parallel with the first swivel shaft. The two toothed wheel segments provide that, when the holder is swivelled away, at the same time a superimposed movement of the second air nozzle takes place around its swivel shaft.
In a further development of the invention, it is provided that the holder is loaded by means of a spring element in the direction of the operating position in which it rests against a stop. The preferably adjustable stop therefore secures the exact operating position, in which case the forced guiding between the two air nozzle provides that both air nozzles take up the correct operating position.
In a development of the invention, it is provided that two adjacent drafting units respectively are combined to one structural component which has a supporting element for mounting the structural component on a machine frame, in which case the supporting element comprises the first swivel shaft for the holders of the air nozzles of the two drafting units. This development results in the advantage that the drafting unit and the air nozzles are always arranged at correct distances from one another which are free of mounting tolerances. This results in the special advantage that the structural component can be mounted in the manufacturing plant and correspondingly can also be adjusted by means of special tools.
In a further development of the invention, it is provided that the supporting element is constructed as a frame which has two supports extending in the passage direction of a fiber material to be drafted and accommodating bottom rollers constructed as roller sections, and which has two transverse supports of which one is used as the swivel shaft for the holders of the air nozzles and the other one is used as a holding rod for a loading arm accommodating top rollers. This development is also advantageous when the air nozzles are not connected with one another by means of a forced guide.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.